COST Action is an interdisciplinary research network that brings researchers and innovators together to investigate a topic of their choice over the span of four years (European Cooperation in Science & Technology, cost.eu, 2025).

This August, four European research networks joined forces in Oxford, United Kingdom, for a summer school with around 50 participants from across the globe. The COST Actions involved were:

1. 3DForEcoTech – Three-dimensional Forest Ecosystem Monitoring and Better Understanding by Terrestrial-based Technologies. This network focuses on the use of terrestrial laser scanners and unmanned aerial vehicles in forestry and on how to process such data, including point clouds. It is, for example, possible to scan a forest, segment the point cloud into woody and leafy components, and then model wildfire risk based on accurate fuel estimates.
2. ARiF – Augmented Reality in Forestry. This network promotes the use of augmented reality. One demonstration showed glasses with an integrated screen overlaying digital information onto the real world. A forester could wear such glasses to see which trees should be cut or left standing. Or, while walking through the forest, the glasses could display the boundaries between land parcels of different owners.
3. PANGEOS – Pan-European Network of Green Deal Agriculture and Forestry Earth Observation Science. This network advances the integration of remote sensing in precision agriculture and forestry. For example, we learned how to use time series of satellite images to track the phenology of tree species. Some species begin shedding their leaves earlier in autumn than others — a difference detectable from space, which can then be used to map species distributions.
4. CLEANFOREST – Joint Effects of CLimate Extremes and Atmospheric depositioN on European FORESTs. This network studies how global change drivers impact forest ecosystems. One example involved dendrometers, devices that measure tree diameter changes with micrometer precision every hour. These data reveal how trees respond to their environment: in cold weather, for instance, stems shrink as nutrients move to the roots and water transport halts. Old trees (>100 years) often grow only a few micrometers per year.

All the participants shared one thing in common: a deep concern for trees. Prof. Dr. Yadvinder Malhi from the University of Oxford compared trees to dinosaurs, members of the megaflora that can far outlive a human lifespan and tower above us, making them endlessly fascinating. Prof. Dr. Mat Disney from University College London explained that the UK has the least forest cover in Europe, but the most old and ancient trees (over 1,000 years old). This is largely due to cultural traditions and strong identification with these trees. People actively care for them, pruning or supporting heavy branches to prolong their lives. Both professors cautioned against focusing solely on carbon in ecosystem assessments. While carbon storage is important, an exclusive focus on it risks neglecting the many other vital ecosystem services that forests provide.

The program also included contributions from design and gamification experts, who showed us how to create a 3D digital model of a tree viewable on a smartphone. Try it yourself (e.g., using Google Chrome with your camera enabled): https://8th.io/x29ut

The exchange with fellow PhD students and experts was both enriching and inspiring, and Oxford even surprised us with dry, sunny weather.

Text and photographs: Samuel Hepner